Re: [Qemu-devel] Is the use of bdrv_getlength() in parallels.c kosher?

[Denis V. Lunev]

On 08/04/2017 03:31 PM, Markus Armbruster wrote:
> Same question for allocate_clusters() in parallels.c, commit 5a41e1f,
> modified in commit ddd2ef2:
>
>     if (s->data_end + space > bdrv_getlength(bs->file->bs) >> 
> BDRV_SECTOR_BITS) {
>
> bdrv_getlength() can fail.  Does it do the right thing then?  For what
> it's worth, the comparison of its value is signed.
>
> There's another one in parallels_open():
>
>     if (!(flags & BDRV_O_RESIZE) || !bdrv_has_zero_init(bs->file->bs) ||
>             bdrv_truncate(bs->file, bdrv_getlength(bs->file->bs),
>                           PREALLOC_MODE_OFF, NULL) != 0) {
>         s->prealloc_mode = PRL_PREALLOC_MODE_FALLOCATE;
>     }
the same as in the previous letter. Saniti checks will not harm.
I'll make a patch.

Thank you for the suggestion.

Den